Hackers involved in the data breach at health insurer Anthem may have ties to the Chinese government, according to a news report.

Investigators see techniques used by a nation-state attacker, with
China a leading suspect, reported Bloomberg Business. The news report cited information from three people close to the investigation,which is being conducted by the FBI and private cybersecurity firm Mandiant.

The investigation is in its early stages, but some of the software and techniques used in the Anthem attack are similar to attacks used almost exclusively in the past by China, according to the Bloomberg article.

The personal information, including Social Security numbers and email addresses, of about 80 million people may be exposed in the breach, according to Anthem. Anthem has 37.5 million subscribers for its health plans, and more than 68 million people are customers of its affiliated companies under brands including Blue Cross and Blue Shield, Empire Blue Cross and Amerigroup.

Credit card numbers and medical information don't appear to be compromised in the breach, according to Anthem.

Anthem reported the breach Wednesday, saying it was the victim of a "very sophisticated external cyber attack."

Representatives of the FBI and Mandiant weren't immediately available for comment on the news report.

Grant Gross covers technology and telecom policy in the U.S. government for The IDG News Service. Follow Grant on Twitter at GrantGross. Grant's email address is grant_gross@idg.com.